Superior-to-Silver King 115 kV relocation project
SRP received a request from Resolution Copper Mining, LLC ("Resolution"), a private property owner and SRP customer, to relocate a portion of the existing Superior-to-Silver King 115-kilovolt (kV) transmission line, near the town of Superior.
On this page:
About the project
The relocation would occur entirely on Resolution's private property. To support this request, SRP will relocate approximately one mile of the existing 115 kV line to the northwest, adjacent and parallel to an existing transmission line corridor.
Arizona Corporation Commission approval
On May 7, 2026, the Arizona Corporation Commission (ACC) granted authorization related to SRP’s request for a 10-year extension of the existing Superior–Silver King Certificate of Environmental Compatibility (CEC). The authorization grants SRP's application
to amend the CEC for the Superior to Silver King relocation project to authorize the CEC for an additional 10 years through 2037.
Map
Certificate of Environmental Compatibility
On Feb. 6, 2018, the Arizona Corporation Commission (ACC) found it was in the public interest to extend the term of the Certificate of Environmental Compatibility (CEC) by 10 years from Oct. 16, 2017, to Oct. 16, 2027.
On Oct. 4, 2012, the ACC voted unanimously (5-0) to confirm the CEC for the Superior-to-Silver King 115 kV
line. This was originally authorized for five years, expiring Oct. 16, 2017.
In June 2012, SRP and its consultant, URS Corporation, filed an application for a Certificate of Environmental Compatibility (CEC) with the Arizona Corporation Commission, as required by state statute. The CEC application includes environmental studies and a summary of the public outreach activities.
At a public hearing held on Aug. 22, 2012, the Arizona Power Plant and Transmission Line Siting Committee recommended that SRP be granted a CEC.
CEC filing
Below are links to SRP's application for a Certificate of Environmental Compatibility (CEC) for the proposed Superior-to-Silver King 115 kV relocation project. The document is presented in PDF format, with each link going to a separate section of the application.
| Cover | PDF |
| Table of Contents | PDF |
| Introduction | PDF |
| Application for CEC | PDF |
| Project Location Map | PDF |
| Apendix A | PDF |
| Apendix B | PDF |
| Apendix C | PDF |
| Biological Evaluation | PDF |
| Cultural Resources | PDF |
| EXIBIT A: Project Location and Land Use | PDF |
| EXIBIT B: Environmental Studies | PDF |
| EXIBIT C: Biological Wealth | PDF |
| Full CEC application (30 MB) | PDF |
Public outreach
Even though this relocation project is on private property, public outreach and communication about this project were shared using a variety of methods between the months of February 2012 and June 2012.
- Stakeholder briefings
- SRP held two open houses in Superior on April 17, 2012
- Mailer
- Agency and tribal notification letters
- Newsletter
- Project website
- Jurisdictional briefings to Pinal County and Superior
- Newspaper ad
- Presentation from Superior open houses
Contact us
For more information about the project, please call (602) 236-2872(602) 236-2872.
